1. IN A PROCESS FOR PRODUCING A CHLOROPRENE SOL POLYMER HAVING EXCELLENT VISCOSITY STABILITY AND COLOR STABILITY, IN WHICH A CHLOROPREN-CONTAINING MONOMER IS POLYMERIZED IN AN ALKALINE AQUEOUS EMULSION CONTAINING A DIALKYL XANTHOGEN DISULFIDE BUT SUBSTANTIALLY NO FREE SULFUR TO A MONOMER CONVERSION NOT EXCEEDING THAT AT WHICH AN ALL-SOL POLYMER IS OBTAINED, THE IMPROVEMENT WHICH COMPRISES STOPPING THE POLYMERIZATION BEFORE EXCEEDING SAID MAXIMUM CONVERSION, ADDING 0.05 TO 0.6 PARTS BY WEIGHT, PER 100 PARTS OF POLYMER, OF A PHENOLIC ANTI-OXIDANT, AND THEREAFTER ISOLATING THE SOL POLYMER AS A SOLID, NON-EMULSIFIED PRODUCT, THE PHENOLIC ANTIOXIDANT BEING SELECTED FROM THE GROUP CONSISTING OF (A) 2,6-DISUBSTITUTED PHENOLS IN WHICH THE SUBSTITUENTS ARE ALKYL OR CYCLOALKYL RADICALS AND CONTAIN UP TO 12 CARBON ATOMS AND AT LEAST ONE OF THE ALKYL RADICALS IS A TERTIARY RADICAL, AND (B) 2,2''-BIS (6TERT-SUBSTITUTED PHENOLS) IN WHICH THE SUBSTITUENTS ARE ALKYL OR CYCLOALKYL RADICALS AND CONTAIN 4 TO 12 CARBON ATOMS AND THE LINK BETWEEN THE TWO RINGS IS A COVALENT BOND OR A DIVALENT SULFUR OR ALIPHATIC RADICAL.